Splash Screen Stuck on IOS 14.4+

My team is building an app on IOS(Android is fine). The app splash screen gets stuck and the only way to make it process is to turn off wifi. The strange thing, it is only happening on iPhone 6s and iPhone12 running 14.4+. It works on iPhone7 and iPhone11 without any problems. Can someone please advise on what can be done to fix the issue. It is real headache. Thanks

(Android is fine)

That's not a guarantee for anything !

Have you an image on the splashScreen ?
How large is it ?
If several Mbytes, try reduce its size below 1 MB, or even remove, just to see.

Do you access any data for the splash screen from the cloud ?
If so, try to save these data locally (image specifically).
Splash Screen Stuck on IOS 14.4+
 
 
Q